Login With Facebook Account On Mobile

I have a very weird issue with the Facebook login with this game.
Let me keep it simple:

Using wifi - No problem logging in, even though the wifi signal is not strong.
Using own mobile data - Encountering "Connection is not stable, Please try again" on the login screen
Login as Guest - Can enter the game using wifi / own mobile data connection.

Tried reinstalling the app, but the problem still persist.
Do any of you have the same problem?
Please tell me how could I resolve this problem.